Intramedullary fixation assembly and devices and methods for installing the same

ABSTRACT

An intramedullary fixation assembly usable with different long bone types and a guide assembly for guiding deployment of the intramedullary fixation assembly. The intramedullary fixation assembly includes a fixation member that has ends and a curved body extending between the ends. The curved body of the fixation member has a radius of curvature configured to extend through the medullary canal regardless of the long bone anatomy. Fasteners fix the fixation member to the bone fragments and are guided by a guide assembly. The guide assembly includes a guide body defining openings configured to guide the fasteners through openings defined in the fixation member and into the bone fragments. A fixation end of the guide body includes a pair of opposing, converging surfaces that are configured to engage in a positive fit with an exposed end of the fixation member accessible through the side aperture in the first fragment.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to the use of orthopedic fixationdevices and devices for installing the same, and in particular, tointramedullary fixation devices and guides for facilitating installationand fixation of the same.

2. Description of Related Art

Long bone fractures are fairly common in the elderly population, oftendue to the onset of osteoporosis. Long bone fractures may be reduced bythe use of assorted conventional bone plates. For example, a bone platemay be attached to the outside surface of two adjacent fragments of along bone and then secured by inserting bone screws through openings inthe bone plate. Problems may arise with such bone plates, however, inthat the soft tissues covering the bone plates may become irritated bypassage or movement over the bone plates.

An alternative to bone plates are intramedullary nails or rods thatextend through a medullary canal defined within the fractured long bone.The nails or rods are typically fastened to the fractured portions ofthe long bones with bone screws. The nails or rods are placed into themedullary canal by insertion through a hole which is drilled into oneend of the long bone. For instance, to reduce a fractured femur with anintramedullary rod or nail, a hole is drilled through the articularcartilage between the condyles to provide access for the rod. Becausethe intramedullary nails or rods are contained within the medullarycanal, they avoid the problems with soft tissue associated with plates.However, insertion of these rods through holes in the ends of the longsbones requires damaging the articular cartilage on the ends of the longbones.

U.S. Pat. No. 6,527,775 to Warburton (“the '775 patent”), which ishereby incorporated herein in its entirety by reference, describes anintramedullary fixation device used to reduce a distal fracture of theradius. As shown in FIG. 3A of the '775 patent, the intramedullaryfixation device 25 includes an elongated axially extending rod 26 with adistal portion 27 and a proximal portion 28. The fixation device alsoincludes a distal fixation member 30 and proximal fixation members 35.The distal fixation member extends through the distal portion of the rodand into a distal fracture fragment 18. The proximal fixation membersextend through the proximal portion of the rod and the portion of theradius proximal the fracture line. The '775 patent describes avoidingend insertion of the rod through the cartilage of the distal radius byusing a laterally positioned bone window 16 defined in the distalfracture fragment.

Although the '775 patent discloses an intramedullary fixation device forreducing a distal radius fracture without insertion through cartilage onthe end of the distal radius, other long bones, such as the humerus,femur and tibia are also often fractured and require repair.

Therefore, it would be advantageous to have a fixation device for alllong bones that is insertable into the medullary shaft of the longbones. It would also be advantageous if the fixation device were capableof insertion without damaging the articular cartilage of the long bones.

BRIEF SUMMARY OF THE INVENTION

The present invention addresses the above needs and achieves otheradvantages by providing an intramedullary fixation assembly usable withdifferent long bone types and a guide assembly for guiding deployment ofthe intramedullary fixation assembly. The intramedullary fixationassembly includes a fixation member that has ends and a curved bodyextending between the ends. The curved body of the fixation member has aradius of curvature extending from a first end configured to extendbetween a side aperture defined in a first fragment through the medularycanal and into a second fragment, regardless of the type of the longbone. Fasteners are used to fix the fixation member to the bonefragments and are guided by a guide assembly. The guide assemblyincludes a guide body defining openings configured to guide thefasteners through openings defined in the fixation member and into thebone fragments. A fixation end of the guide body includes a pair ofopposing, converging surfaces that are configured to engage in apositive fit with an exposed end of the fixation member accessiblethrough the side aperture in the first fragment. Advantageously, thepositive fit facilitates accurate positioning of the guide body and, asa result, of the fixation member fasteners.

In one embodiment, the present invention includes an intramedullaryfixation assembly for repairing any of a plurality of long bone types.Each of the long bones defines a medullary canal fractured into at leasta first and second adjacent bone fragments. The first bone fragment hasa free end with an articular cartilage surface and defines a sideaperture. The side aperture is positioned subjacent the articularcartilage surface of the first bone fragment and extends into themedullary canal. Included in the intramedullary fixation device are aplurality of fasteners (e.g., a first fastener and a second fastener)each having an elongate body with a head end and an opposite,bone-securing end. A fixation member of the intramedullary fixationdevice includes a first end, a second end and a curved body extendingbetween the first and second ends. The curved body defines at least onefastener opening positioned proximate the first end and configured toallow passage of the first fastener therethrough and into the first bonefragment. Also defined by the curved body is a second fastener openingpositioned proximate the second end and configured to allow passage ofthe second fastener therethrough and into the second bone fragment. Thecurved body has a radius of curvature extending from the first end thatis configured to allow passage of the fixation member through the sideaperture of the first bone fragment and into the medullary canal untilthe first end of the fixation member is positioned adjacent the sideaperture, and within a portion of the medullary canal defined within thefirst bone fragment, and the second end of the fixation member ispositioned within a portion of the medullary canal defined within thesecond bone fragment. In this manner, the fixation assembly can be usedto reduce and secure a fracture of any of the various types of humanlong bone types.

In one aspect, the curved body has a smooth, continuous curvature thatextends from its first end to its second end. The radius of curvature ispreferably defined by a centerline extending from the first end to thesecond end. Also, the curved body preferably includes smoothly curvingconcave and convex sides configured to facilitate passage of thefixation member through the side aperture and into the medullary canal.Also, the first and second ends may be tapered to facilitate insertionthrough the side aperture and into the medullary canal.

In another aspect, the same radius of curvature extending from the firstend can be used for a plurality of lengths for the curved body, allowingthe design to be extended to various long bone types. Preferably, theradius of curvature extending from the first end ranges from between 1.5to 5 inches, and more preferably, about a radius of curvature ofapproximately 2 to 4 inches, or 2.6 to 3.4 inches.

In another embodiment, the present invention includes a guide assemblyfor facilitating placement of a plurality of bone fasteners of anintramedullary fixation assembly through predefined locations on afixation member of the intramedullary fixation assembly. The fixationmember extends through a medullary canal defined within a long bone andhas an exposed end accessible through a side aperture defined by thelong bone. Included in the guide assembly is at least one guide fastenerconfigured to extend into the exposed end of the fixation member so asto be secured to the fixation member. A guide body includes a fixationend and defines a plurality of fastener guide openings. These guideopenings are configured to orient the bone fasteners extending throughthe guide openings with the predefined locations on the fixation member.The fixation end defines an opening configured to allow passage of theguide fastener through the guide body and into the exposed end of thefixation member. The fixation end includes at least one pair of surfacespositioned opposite each other and generally extending in a convergingdirection. These surfaces are, as a result, configured to engage in apositive fit with the exposed end of the fixation member when the guidebody is secured thereto with the guide fastener. This positive fitreduces the motion between the guide body and the fixation member,thereby improving the ability of the guide openings to accurately guidethe bone fasteners through the predetermined locations on the fixationmember.

As an example of the surfaces used for a positive fit, the pair ofsurfaces may be portions of a convex surface or prong configured toextend within a concave surface defined within the exposed end of thefixation member. Preferably, the convex surface is configured to reach apositive fit prior to full contact between the remaining (non-convex andnon-concave) surfaces of the fixation end and the exposed end. In yetanother aspect, there may be additional pairs of surfaces or prongsconfigured for a positive fit, including second, third and fourth pairsof surfaces spaced from each other in a cruciform configuration.

The present invention has many advantages. For example, the inventionhas many attributes that facilitate its use for different types of humanlong bone. Maintaining a constant radius of curvature of a first end ofthe curved body allows for different sized long bones and differenttypes of long bone to be accommodated merely by extending the arcfurther to produce a greater “hook” on increasing sizes of fixationmembers. This overcomes the increase in not only the length of the longbone, but also the increase in distance between widened end and width ofthe medullary canal, facilitating its use on different and larger typesof long bones. It has also been determined that use of a radius ofcurvature in the ranges of 1.5 to 5 inches facilitates use withdifferent types of long bone, especially when the curved body curvescontinuously along its length and the ends are tapered for easyinsertion. The use of a cruciform shape and positive fit or wedge effectused for the concave indentations and the prongs provides rotational andtranslational stability of the fixation member when attached to theguide assembly. In addition, the positive fit or wedge effect operatesto center and reduce micro-motion between the targeting guide and therest of the guide assembly.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, which are not necessarily drawn toscale, and wherein:

FIG. 1 is a perspective view of a long bone fracture repaired using anintramedullary fixation assembly of one embodiment of the presentinvention;

FIG. 2 is an elevation view of the long bone fracture and intramedullaryfixation assembly of FIG. 1;

FIG. 3 is a side elevation view of a fixation member of theintramedullary fixation assembly of FIG. 1;

FIG. 4 is another side elevation view of a fixation member of theintramedullary fixation assembly of FIG. 1;

FIG. 5 is another side elevation view of a fixation member of theintramedullary fixation assembly of FIG. 1;

FIG. 6 is another side elevation view of a fixation member of theintramedullary fixation assembly of FIG. 1;

FIG. 7 is a sectional view of the fixation member of FIG. 6;

FIG. 8 is a sectional view of the fixation member of FIG. 6;

FIG. 9 is a sectional view of the fixation member of FIG. 6;

FIG. 10 is a sectional view of the fixation member of FIG. 6;

FIG. 11 is a sectional view of a portion of the fixation member and apair of bone fasteners of the intramedullary fixation assembly of FIG.1;

FIG. 12 is a sectional view of one of the bone fasteners shown in FIG.11;

FIG. 13 is a side elevation view of a fixation member of anotherembodiment of the present invention, including a stem extending from oneof its ends;

FIG. 14 is another side elevation view of the fixation member of FIG.13;

FIG. 15 is a plan view of a head end of one of the bone fasteners shownin FIG. 11;

FIG. 16 is a side elevation view of the bone fastener shown in FIG. 15;

FIG. 17 is a sectional view of the bone fastener shown in FIG. 15;

FIG. 18 is a plan view of a head of a k-wire for use as a bone fastenerin another embodiment of an intramedullary fixation assembly of thepresent invention;

FIG. 19 is a sectional view of the k-wire shown in FIG. 18;

FIG. 20 is a side elevation view of an outrigger frame of a guideassembly of another embodiment of the present invention shown in FIG.53;

FIG. 21 is a plan view of the outrigger frame of FIG. 20;

FIG. 22 is another side elevation view of the outrigger frame of FIG.20;

FIG. 23 is plan view of a targeting guide of the guide assembly of thepresent invention shown in FIG. 53;

FIG. 24 is a side elevation view of the targeting guide of FIG. 23;

FIG. 25 is another plan view of the targeting guide of FIG. 23;

FIG. 26 is a sectional view of the targeting guide of FIG. 25;

FIGS. 27-30 are various views of the targeting guide of anotherembodiment of the present invention;

FIG. 31 is a side elevation view of a screw-in drill guide which is partof the outrigger frame of FIG. 20;

FIG. 32 is a sectional view of the screw-in drill guide of FIG. 31;

FIG. 33 is a side elevation view of a drill guide of another embodimentof the present invention;

FIG. 34 is a sectional view of the drill guide of FIG. 33;

FIG. 35 is a side elevation view of a screw guide of a guide assembly asshown in FIG. 59;

FIG. 36 is a sectional view of the screw guide of FIG. 35;

FIG. 37 is a side elevation view of guide member of the outrigger frameshown in FIG. 20;

FIG. 38 is a sectional view of the guide member of FIG. 37;

FIGS. 39 and 40 show a perspective view of attachment of a set of fourprongs on the guide member of FIG. 37 within a set of four recessesdefined in an end of the fixation member shown in FIG. 6;

FIG. 41 is an enlarged view of the prongs and recesses of FIG. 39forming an interference fit;

FIGS. 42 and 43 show a side elevation view of a fastener driving drillbit of another embodiment of the present invention;

FIG. 44 is a side elevation of a drill bit of another embodiment of thepresent invention;

FIG. 45 is a plan view of a hand driver of another embodiment of thepresent invention;

FIG. 46 is a side elevation view of the hand driver of FIG. 45;

FIG. 47 is a sectional view of a cannulated drill bit of anotherembodiment of the present invention;

FIG. 48 is a side elevation view of a trialing broach assembly ofanother embodiment of the present invention;

FIG. 49 is a side elevation of a handle of the trialing broach assemblyshown in FIG. 48;

FIG. 50 is a side elevation view of a depth indicator of anotherembodiment of the present invention;

FIG. 51 is a sectional view of the depth indicator of FIG. 50;

FIG. 52 is a perspective view of the trialing broach assembly of FIG. 48show inserted into a long bone;

FIG. 53 is a perspective view of the fixation member of FIG. 3 connectedto the guide assembly of the present invention;

FIG. 54 is a perspective view of the fixation member and guide assemblyof FIG. 53, wherein the fixation member has been positioned in themedullary canal of the fractured long bone;

FIG. 55 is a perspective view of the guide assembly and fixation membershown in FIG. 54, wherein the guide assembly is guiding drilling throughan opening in the fixation member and into the long bone;

FIG. 56 is a perspective view of the guide assembly and fixation membershown in FIG. 54, wherein drilling is being guided through anotheropening in the fixation member;

FIG. 57 is a perspective view of the guide assembly and fixation memberof FIG. 54 guiding placement of a bone fastener, such as the bonefasteners shown in FIGS. 11 and 12, through the bone and the opening inthe fixation member;

FIG. 58 is a perspective view of placement of another bone fastenerusing the assemblies of FIG. 57;

FIG. 59 is a perspective view of placement of yet another bone fastenerusing the assemblies of FIG. 57;

FIG. 60 is a sectional view of a long bone and a fixation member ofanother embodiment of the present invention, wherein the fixation memberincludes a split tail;

FIG. 61 is a sectional view of a bone fastener of another embodiment ofthe present invention positioned within the split tail of the fixationmember of FIG. 60;

FIG. 62 is a sectional view of a long bone and a fixation member ofanother embodiment of the present invention, wherein the fixation memberincludes a split tail;

FIG. 63 is a sectional view of the long bone and fixation member of FIG.62 wherein one arm of the split tail is threaded to allow splaying ofthe split tail FIG. 64 is a side elevation view of an impactor having aU-shaped end and fixation member defining U-shaped slots for receivingthe end of the impactor in another embodiment of the present invention;

FIG. 65 is a sectional view of the U-shaped impactor and slot of FIG.64;

FIGS. 66-72 show assorted views of an S-shaped, positive fit connectionbetween a guide assembly and fixation member of another embodiment ofthe present invention;

FIG. 73 is a side elevation view of a fixation member of anotherembodiment of the present invention having a bow tilt;

FIG. 74 is a side elevation view of a fixation member of anotherembodiment of the present invention having a linear offset; and

FIG. 75 is a side elevation view of a fixation member of anotherembodiment of the present invention having an angular bend.

DETAILED DESCRIPTION OF THE INVENTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which some, but not allembodiments of the invention are shown. Indeed, this invention may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will satisfy applicable legalrequirements. Like numbers refer to like elements throughout.

An intramedullary fixation assembly 10 of one embodiment of the presentinvention is shown installed in a long bone 11 of a patient in FIGS. 1and 2. The long bone could be any of a number of long bones, such as afemur, tibia, radius or humerus. The fixation assembly 10 is most suitedto repairing fractures of the long bone 11 wherein the fracture is atone end near an articular cartilage surface 12 and wherein it is desiredto leave the articular surface undisrupted during the repair. Also, thelong bone includes a widened end 13 that supports the articularcartilage surface which tapers to a more narrow shaft 14. Extendingwithin the shaft 14 and a portion of the widened end 13 is a medullarycanal 15. Generally, every type of long bone will have theafore-described characteristics, such as the shaft 14 being relativelynarrower than the end 13. However, the proportional geometry of thedifferent long bones will vary due to their biology and function.

When referred to herein, the terms “different long bones,” “various longbones,” and other, related terms, do not refer to the same type of longbone in different people, but different types of long bones, such as afemur versus a tibia, or radius, or humerus. In addition, theintramedullary fixation assembly could be used to repair somewhat morecomplex fractures, but is shown being used to repair a first bonefragment 16 separated from a second bone fragment 17 by a singlefracture line 18. A side aperture 19 is defined in a lateral surface ofthe widened end 13, subjacent the articular cartilage surface 12, toallow insertion of the intramedullary fixation assembly 10.

Generally, the intramedullary fixation assembly 10 includes an elongatefixation member 20 and a plurality of fasteners 21 that extend throughthe elongate fixation member to attach it to the long bone 11 above andbelow the fracture line 18 and thereby reduce the fracture, for exampleas shown in FIGS. 1 and 2. The elongate fixation member 20 preferably,when positioned within the medullary canal 15 of the long bone 11(regardless of its type), has a first end 22 positioned adjacent theside aperture 19. Extending from the first end, through the rest of theaperture and into the medullary canal 15 of the first bone fragment 16,is a curved body 24 (shown in broken lines in FIGS. 1 and 2) of thefixation member 20. The curved body 24 extends to a second end 23 whichis positioned within the medullary canal 15 of the second bone fragment17. Advantageously, a radius of curvature of the curved body 24 isselected to promote smooth insertion of the curved body through the sideaperture 19 and into the medullary canal 15 despite differences in thewidth of the widened end 13 and the shaft 14 and medullary canal 15between the various types of long bone 11.

For example, one embodiment of the fixation member 20 of the presentinvention is shown in FIGS. 3-14. The first end 22 of the fixationmember 20 has two intersecting flat surfaces, including an exposed firstend surface 27 that is accessible through the side aperture 19 and anadjacent first end surface 28 that is at a right angle to the exposedsurface, as shown in FIG. 4. The second end 23 of the fixation member 20has a rounded profile with a radius of about 0.08 inches, as shown inFIG. 4, and edges rounded to about a 0.06 inch radius, as shown in FIG.5.

The curved body 24 of the fixation member 20 includes a convex side 29and a concave side 30 that are on opposite sides of the curved body. Thesides have radii of curvature with a similar center, but the center ofthe convex side changes so that the sides converge in a slight taper asthey extend to the second end 23, as shown in FIG. 4. For instance, theradius of curvature of the concave side 30 is about 3.12 inches and theradius of curvature of the convex side 29 is about 3.36 inches near thefirst end 22 when measured from a first center 31 positioned about 2.14inches from the plane of the adjacent first end surface 28 and about2.47 inches from the plane of the exposed first end surface 27. But, theradius of curvature of the convex side 29 shifts to about 2.68 inches ata second center 32 that is positioned about 1.89 inches from the planeof the adjacent first end surface 28 and about 1.5 inches from the planeof the exposed first end surface 27.

Notably, this shift produces the taper near the second end 23 of thefixation member 20. Also notable is that maintaining a constant radiusof curvature near the first end 22 of the curved body 24 allows fordifferent sized and different types of long bones to be accommodatedmerely by extending the arc further to produce a greater “hook.” Thisovercomes the increase in not only the length of the long bone 11, butalso the increase in distance between widened end 13 and width of themedullary canal 15, facilitating its use on different and larger typesof long bones. If measured from the centerline of the curved body 24,the radius of curvature can actually be constant between the sides 29,30 and the ends 22, 23 regardless of the amount of taper. This radius ofcurvature can also be maintained while the arc length of the curved body24 is extended to account for increased length of the long bone 11 andincreased offset between the side aperture 19 and the position of themedullary canal 15. As a result, an entire kit of fixation members couldhave the same radius of curvature but be usable in different types andlengths of long bones.

A second pair of opposite, side surfaces 33 extend between the convexside 29 and concave side 30, as shown in FIGS. 3 and 5. Similar to theconvex side 29 and concave side 30, the side surfaces 33 taper slightlytoward each other as they extend from the first end 22 to the second end23 of the curved body 24. However, the side surfaces 33 in theillustrated embodiment are relatively planar, as opposed to the curvedshape of the sides 29, 30. Advantageously, the taper of the sides 29,30, 33, the continuous curve of the curved body 24 between the ends 22,23 and the rounded profile of the second end 23 help to facilitateinsertion through the side aperture 19 and into the medullary canal 15.Note that the term “continuous” differs from “constant” in reference tocurvature herein in that a continuous curvature is not necessarily aconstant curvature. In addition, the use of radii of curvature withinabout the ranges cited above, with variations of about 1.5 to 5 inches,allow the fixation member 20 to be employed in different (preferablyhuman) long bones with only variations in the overall length of thefixation member.

There may be some adaptations of the fixation member 20 beyond extensionof the arc length, such as through the application of a tilt. The tiltwould generally not be in the curvature defined by the convex andconcave sides 29, 30 to accommodate curvature in different long bones.For example, a volar tilt may be used to accommodate the volar tilt inthe saggital plane of the human radius. In this instance, volar tiltfacilitates better filling of the medullary canal of the distal radiusand can improve stabilization of the fixation member 20. Generally, thetilt can be accomplished, for example, through the use of a radial bow,as shown in FIG. 73, a linear offset, as shown in FIG. 74, or an angularbend, as shown in FIG. 75. The radial bow ranges from about 4 to 8inches (100 to 200 mm) of curvature. The linear offset is about 2 to 5mm and the angular bend is about a 10° to 20° angle.

To allow passage of the fasteners 21 through the fixation member, aplurality of fastener openings are defined in the fixation member. Thesefastener openings include a side aperture accessible fastener opening34, a pair of fastener openings 35 extending between the curved convexside 29 and concave side 30, and fastener openings 36 extending betweenthe side surfaces 33. The fastener opening 34 extends from the exposedfirst end surface 27 (which is accessible through the side aperture 19when the fixation member 20 is installed) through a portion of thecurved body 24 and to the convex side 29, as shown in FIGS. 4 and 5. Thefastener opening 34 includes a guide portion 38 and a fastener headportion 39 that is generally more narrow than the guide portion. Both ofthe portions are threaded, as shown in FIGS. 7 and 8, to facilitate asecure fit by the fasteners 21 and various installation devices, as willbe described in more detail below. Defined around the periphery of theguide portion 38 of the fastener opening 34 are four concave channels,recesses or indentations 40. These indentations are arranged in a cross,or cruciform, shape each radiating out from the fastener opening 34 andspaced 90° from each other. As will be described in more detail below,the concave indentations 40 serve to provide for a secure, positive fitwith a guide assembly 50.

The pair of fastener openings 35 which extend between the sides 29, 30extend through the curved body 24 nearer the first end 22 so as to bewithin the first bone fragment 16, as shown in FIG. 5. Each of thefastener openings also has a threaded fastener portion 39 similar to thefastener opening 34, but a non-threaded guide portion 38, as shown inFIGS. 9 and 10. These fastener openings 35 extend at different,divergent angles than each other and the orientation of the fasteneropening 34 which is relatively orthogonal with respect to the exposedfirst end surface 27 and the convex side 29, as shown in FIGS. 3. As aresult, the fastener openings of the present invention (such as thefastener openings 35) need not all be aligned with the axis of thefixation member.

These different angles improve fixation by allowing angled insertion ofthe fasteners into different portions of the first bone fragment 16, asshown in FIGS. 1 and 2. In addition, the angles of the fastener openings34, 35 may be configured so that the fasteners extend subjacent to thearticular cartilage for improved fixation. Generally, this will requirethe fastener openings 34, 35 to extend at some acute angle, such as anangle between about 50° and 85° (depending on the origin of the fasteneropening), and preferably about 60° to 70°, with respect to the fixationmember body. Basically, these angles are to match the inclination angleof the articular surface so as to provide a buttress effect for thearticular cartilage. For instance, the ulnar inclination angle of thearticular cartilage on the radius is about 23° (resulting in a 67°fastener opening angle). The buttress effect is also improved by thesub-chondral placement of the first end surface 28 that is adjacent andat a right angle with respect to the exposed first end surface 27 so asto underlie the articular cartilage.

In the illustrated embodiment shown in FIGS. 4 and 6, three fasteneropenings 36 are defined in the curved body 24 at a position nearer thesecond end 23 of the fixation member 20. The two outer ones of thefastener openings 36 are configured to receive threaded fasteners 21,similar to the fastener openings 34, 35, but the center one of thefastener openings 36 is configured to receive a relatively smallerdiameter k-wire fastener 41, as shown in FIG. 6. Preferably, the largerof the fastener openings 36 are not threaded to allow a slip fit of thethreaded fasteners 21 without damaging the threads, as will be describedbelow.

The threaded fasteners 21 are shown in greater detail by FIGS. 15-17 andthe k-wire fastener 41 by FIGS. 18 and 19. Each of the fasteners 21, 41is shown as being driven by a Phillips-type, or cruciform-type, head(FIGS. 15, 17 and 18), but may be configured for mating with a driver inany number of ways, such as with an Allan-type head or flat head. Eachof the illustrated threaded fasteners 21 includes a head 42, a threadedshaft 43, a non-threaded shaft portion 45 and a bone-securing end 44, asshown in FIG. 16. The head 42 of each of the threaded fasteners 21 has alarger diameter than its shaft 43, so as to prevent the threadedfastener from passing through tapped openings in the first layer ofcortical bone. However, the diameter of the head 42 is still smallenough to pass through a screw guide 51, or other guide, positioned bythe guide assembly 50 within the guide portion 38, as will be describedin more detail below.

When the threaded fasteners 21 are inserted through the openings 34, 35and into the first bone fragment 16, the head is configured to reside inthe guide portion 38, the threaded shaft 43 in the threaded fastenerportion 39 and the bone-securing layer is configured to attach to thedistant layer of cortical bone opposite the side aperture 19 andsubjacent the articular cartilage surface 12, as shown in FIGS. 1 and 2.When inserted through the openings 36 and into the second bone fragment17, the threaded shaft 43 is configured to attach to the first layer ofcortical bone, the non-threaded shaft portion 45 is configured to residein the openings 36 in a slip fit and the bone-securing end 44 isconfigured to attach to the distant layer of cortical bone opposite thefirst layer of cortical bone, as shown in FIG. 11. The fastener head 42is configured to abut the first layer of cortical bone, and may have arounded shape to minimize irritation of the overlying tissues, as shownin FIG. 12. Notably, when used in the openings 36, the threadedfasteners 21 become bi-cortical screws, firmly attaching to two layersof cortical bone. As another option, the non-threaded shaft 45 mayinclude a chamfer 63 to help locate the screw in the openings 36 as itis advanced through the fixation member 20.

The bone-securing end 44 preferably has threads and an outer diameterthat is smaller than the minimum, trough diameter of the threads on thethreaded shaft 43 and the diameter of the un-threaded shaft portion toprevent the bone-securing end from locking up or fretting the threadswhen passing through the fastener portion 39. A neck 46 on each of thethreaded fasteners 21 also prevents lockup by providing space betweenthe threaded fastener shaft 43 and fastener head 42, as shown in FIGS.16 and 17. As shown in FIG. 19, the k-wire fastener 41 also includes afastener head 42, a neck 46, a threaded shaft 43 and a non-threadedshaft portion 45, but its bone securing end 44 is not threaded foreasier insertion as the first fastener.

During installation, the threaded shaft 43 of one of the threaded ork-wire fasteners 21, 41 mates with the threaded fastener portion 39 ofits respective one of the fastener openings 34, 35 and 36 and thebone-securing end 44 extends into the long bone 11 for a secure fit, asshown in FIGS. 1 and 2. It should be noted that although two types offasteners are described herein that are preferred, other types offasteners may also be employed, including other types of wires, screws,etc., and still be within the purview of the present invention as longas some portion of the fastener secures itself to the fixation member 20and another portion to the long bone 11.

FIGS. 20-30 illustrate the guide assembly 50 of the present inventionthat is used to position the screw guide 51, a screw-in drill guide 52and a plurality of other drill guides 53, shown in FIGS. 31-36. Theguide assembly 50 includes an outrigger frame 54 having a curved,hook-shaped body 55 including a first end 56 for positioning fasteners21 within the first end 22 of the fixation member 20 and the first bonefragment 16, and a second end 57 for positioning fasteners within thesecond end 23 of the fixation member and the second bone fragment 17, asshown in FIGS. 20-22.

The outrigger frame 54 also includes a guide member 58 that has atruncated pyramid shape and extends from a flat surface of the first end56 of the hook-shaped body 55, as shown in FIGS. 20 and 22. The guidemember 58 tapers as it extends outward from the hook-shaped body andends in four prongs 59, as shown in FIGS. 37-40. Each of the prongs 59has a rounded shape with opposing edge surfaces 60 angled toward eachother (i.e., they are generally converging) as they extend outwards fromthe end of the truncated pyramid shape. These converging surfaces arespaced so as to fit into similarly shaped, but somewhat smaller, concaveindentations 40 in a positive, or interference, type fit, as shown inFIGS. 39-41. The guide member 58 and its subjacent portion of thehook-shaped body 55 define a stepped opening 61, as shown in FIG. 38,that is sized to receive the screw-in drill guide 52 (shown in FIGS. 31and 32). The stepped opening 61 includes shoulders 62 that prevent thepassage of the screw-in drill guide 52.

The screw-in drill guide 52 includes a burled knob 65, an elongate shaft66, a tapered shoulder 67 and a threaded tip 68. The burled knobprovides 65 a gripping surface for tightening the screw-in drill guide52 and its relatively large diameter acts as a stop against passage ofthe screw-in drill guide through the stepped opening 61 when insertedtherein and tightened. The elongate shaft 66 extends from the burledknob and tapers at the tapered shoulder 67 down to the diameter of thethreaded tip 68. This shape allows passage of the threaded tip throughand out of the stepped opening 61 so that the threaded tip 68 can beadvanced into the threads of the guide portion 38 of the fasteneropening 34. Defined within the screw-in drill guide 52 is a guideopening that extends from the burled knob 52 through to the threaded tip68 and includes a large diameter portion 70 that tapers to a smalldiameter portion 71 near the threaded tip, as shown in FIG. 32. Thischange in diameter helps to concentrically center the fasteners 21 asthey are advanced through the screw-in drill guide 52 and into thefastener opening 34 defined in the fixation member 20, as will bedescribed below.

When the threaded tip is advanced into the threads of the guide portion38, the guide member 58 and its prongs 59, which are also spaced in acruciform or cross pattern similar to the indentations 40, are advancedinto the indentations, as shown in FIG. 40. The cruciform pattern,combined with the positive fit, firmly locks the outrigger frame 54 tothe fixation member 20 before and during guidance of insertion of thevarious fasteners 21, 41. This firm attachment guards against relativemotion of the guide assembly 50 with respect to the fixation member 20,so that misalignment of the guides 51, 52, 53 is reduced even with justa single point of attachment of the guide assembly to the fixationmember.

The cruciform shape and positive fit are particularly effective atrestricting rotation between the guide assembly and fixation member,which can be a problem due to the relative length and cantileveredconfiguration of the guide assembly and fixation member, especially onthe larger long bones such as the tibia and femur. It should be noted,however, that the positive fit of the prongs 59 in the concaveindentations 40 could be accomplished in other ways, such as by havingthe indentations on the guide member 58 instead of the exposed first endsurface 27 of the fixation member 20.

In addition, different numbers and configurations of the prong andindentation arrangement are also possible to achieve a firm positivefit, even though the cruciform arrangement is preferred for reducingrotational motion. For instance, the positive or press fit may beimplemented or facilitated, as shown for example in FIG. 41, by slightlyover-sizing a male fitting portion (e.g., the prongs 59) with respect toa female portion (e.g., the concave indentations 40) so that the angledopposing surfaces (e.g., converging edge surfaces 60) are in contact andthe tip of the male portion, and other remaining flat surfaces haveminimal contact to allow the angled surfaces to wedge into each other.

Returning to a discussion of the first end 56 of the hook-shaped body 55of the outrigger frame 54, the first end 56 further supports two screwguides 51 that are integrally connected to, and extend from, the firstend of the hook-shaped body, as shown in FIGS. 20-22. These screw guides51 are cylindrical tubes that define openings extending therethrough andare oriented so as to have an axis collinear and aligned with the axesof the of the pair of openings 35 defined in the curved body 24 of thefixation member 20. Preferably, the screw guides 51 are oriented so thatthe fasteners 21 extend at an angle into the first bone fragment 16right below the articular cartilage surface 12, as shown in FIGS. 1 and2. In addition to the screw guides 51, the first end 56 also includes ahandle mount 37 defining a threaded opening.

Referring now to the second end 57 of the hook-shaped body 55, there issupported a channel member 72 of the outrigger frame 54 that extendsaway from the second end of the hook-shaped body. The channel member 72has an elongate rectangular shape, as shown by FIGS. 21 and 22, andincludes a pair of channel arms 73 extending away and along the lengthof the rectangular shape, as shown in FIGS. 20 and 21. Each of the armsdefines an angled surface 74 extending toward the other one of the armsand the arms are spaced from each other and parallel so as to define achannel. Extending into the channel defined between the arms 73 is astop 75. In addition, the second end 57 and the channel member 72 definea locking member opening 76 that extends into the channel between thearms 73. The locking member opening 76 is sized and includes threads toreceive advancement of a locking member 77, as shown in FIGS. 20 and 22.The locking member includes its own burled knob 78 to facilitate itsadvancement and also has a frusto-conical shaped distal locking tip 79that extends out of the locking member opening 76 and into the channelbetween the arms 73 when the locking member 77 is fully advanced, asshown in FIGS. 20 and 21.

Also included in the guide assembly 50 is a targeting guide 80 (as shownin FIGS. 23-26) that is configured to support and orient the drillguides 53 and screw guides 51 that are used to guide insertion of thefasteners 21, 41 through the fixation member 20 and into the long bone11. Different targeting guides 80 can also be used for different sizedfixation members 20 (e.g., as shown in FIGS. 27-30), and can be employedin right and left handed configurations depending on the type of longbone being treated and the orientation of the side aperture 19. Thetargeting guide includes a guide portion 81 and a slide attachmentportion 82. The guide portion 81 defines a plurality of guide openings83 sized for the passage of screw guides 51 or drill guides 53 sized forthreaded fasteners 21 or for the smaller diameter k-wire fasteners 41.The guide openings 83 are positioned along an arc (as shown in FIGS. 23and 25) to correspond to the placement of the openings 36 through theside surfaces 33 of the curved body 24 so as to guide the fasteners 21,41 into the openings 36. Optionally, one of the smaller diameteropenings 83 may be placed to orient insertion of one of the k-wirefasteners 41 external to the fixation member 20 to avoid additionalholes in the fixation member and provide for temporary securing of theguide assembly 50.

The slide attachment portion 82 is generally rectangular and defines apair of slots 84 that extend to one edge of the side attachment portion.As is shown in FIG. 26, these slots are defined by a pair of angled,opposing surfaces 85. In addition, at about a midpoint along one edge ofthe slide attachment portion 82 is defined a circular centering divot 86with sloped sides, as shown in FIGS. 24 and 26. During attachment of thetargeting guide 80 to the channel member 72, the pair of slots 84 of theslide attachment portion 82 are inserted between the channel arms 73until approximately at the end of travel of the slots. Then, the lockingmember 77 is advanced in the opening 76 until the locking tip 79 entersthe centering divot 86. The sloped sides of the centering divot 86interact with the sloped edges of the locking tip 79 which forces thetargeting guide 80 to center and forms a relatively tight, positive fit.Once the locking tip 79 bottoms within the centering divot 86, furtheradvancement of the locking tip pushes the angled, opposing surfaces 85of the slots against the angled surfaces 74 of the channel arms 73. Thisalso has the effect of centering the targeting guide 80 between thechannel arms 73 and also forms a relatively tight, positive fit. In thismanner, a positive fit is used once again to ensure tight assembly ofthe parts and accurate guidance for the insertion of various fasteners21, 41.

As shown in FIGS. 33-36, each of the screw and drill guides 51, 53include a grip flange 48 at one end of an elongate shaft 49 that definesteeth 47 at its other end. Defined within the elongate shaft 49 of thedrill guide is a guide shaft opening that tapers from a wider tonarrower diameter near the teeth 47, as shown in FIG. 34. Thiscorresponds with the dual diameter drill bit 90 shown in FIG. 44,wherein the larger diameter of the drill bit prevents travel of thedrill bit beyond the shoulder defined within the shaft 49 of the drillguide 53 so as to prevent drilling past a selected depth for safety. Theelongate shaft 49 of the screw guide 51 also defines a guide shaft, butthis guide shaft has a constant diameter because, as described above,the fasteners 21, 41 are restrained by the structure of the fixationmember 20 from advancing too far.

During use the drill guides 53 are first inserted into the guideopenings 83 of the guide portion 81 of the targeting guide and areadvanced until the teeth 47 contact skin or bone (so as to preventrotation of the guides). A pilot hole is drilled using the drill bit 90guided by the drill guides 53. Then, the drill guides 53 are removed andscrew guides 51 are inserted in the guide openings 83 until the teeth 47contact skin or bone. The selected one of the threaded or k-wirefasteners 21, 41 are advanced at the end of a driver 91 (as shown inFIGS. 42 and 43) until penetrating the fixation member 20 through one ofthe openings 36 and into the long bone 11 (in this case the second bonefragment 17). The driver 91 or drill bit 90 may be advanced using poweror by hand, such as by a hand driver 92, as shown in FIGS. 45 and 46.

During installation of the intramedullary fixation assembly 10, a k-wireis inserted into a lateral side of the widened end 13 of the long bone11 subjacent the articular cartilage surface 12 and used to guide acannulated drill bit 94, as shown in FIG. 47. The cannulated drill bitclears the side aperture 19 and a conventional bone awl (not shown) isused to open the medullary canal 15 of cancellous bone.

A trialing broach 95, as shown in FIGS. 48 and 52, is pushed, twisted,hammered, etc., into the long bone 11 through the side aperture 19 toapproximate the size of the fixation member 20. The trialing broachincludes a handle 98 and an awl point 99. The handle 98 includes a head100 that facilitates gripping and hammering at one end and a threadedconnector 101 at the other end, as shown in FIG. 49. This threadedconnector is similar to the threaded tip 68 of the screw-in drill guideallowing the exchange of the awl point 99 with other awl points ofdifferent sizes, each having threaded opening at one end similar to thethreaded opening 34 on the fixation member 20. Preferably, the awl point99 has some type of teeth or cutter (as shown symbolically by thecross-hatch pattern 96) to aid in bone removal and sizing.

Advantageously, the trialing broaches 95 may eliminate the need for manyawls and cutting tools. However, other conventional tools, such asreamers and awls could also be employed to clear bone. Each of thebroaches 95 may also include a depth indicator, such as the notch 97shown in FIG. 48, that indicates the correct depth for that size offixation member 20. The depth indicator or notch 97 may include the useof fluorescent paint so as to be easily visually detectable.

Once the side aperture 19 has been formed and the medullary canal 15cleared and sized, an appropriately sized fixation member 20 is selectedbased on the various above-described measurements. The handle 98 of thetrialing broach 95 is removed from the awl point 99 and attached to thethreaded opening defined in the handle mount 37 via the threadedconnector 101 on the handle, as shown in FIG. 53. Then, the outriggerframe 54 of the guide assembly 50 is attached to the fixation member. Inparticular, the screw-in drill guide 52 is extended through the steppedopening 61 of the guide member 58 and its threaded tip 68 is advancedinto the threaded opening 34 of the guide assembly. This assembly matesthe prongs 59 with the concave indentations 40, thereby locking outmicro-motion and rotation between the outrigger frame 54 and thefixation member 20, as shown in FIGS. 39 and 40.

After fixation of the outrigger frame 54, the targeting guide 80 isattached to the channel member 72 by sliding the channel arms 73 withinthe pair of slots 84 on the guide portion 81 until the targeting guideis against the stop 75. Then, the locking member 77 is advanced in theopening 76 until the locking tip 79 enters the centering divot 86. Thesloped sides of the centering divot 86 interact with the sloped edges ofthe locking tip 79 which forces the targeting guide 80 to center andforms a relatively tight, positive fit. Once the locking tip 79 bottomswithin the centering divot 86, further advancement of the locking tippushes the angled, opposing surfaces 85 of the slots against the angledsurfaces 74 of the channel arms 73.

The handle 98 and guide assembly 50 are then used to slide the fixationmember 20, as facilitated by the tapered ends 22, 23 through the sideaperture 19 and into the medullary canal 15, as shown in FIG. 54. Thehandle 98 is then unscrewed from the handle mount 37. As an option, thefixation member 20 may include radio-lucent targeting indicia to aid inpositioning of the fixation member and guide assembly 50. The length ofthe handle 98 allows for easy readjustment of the position of thefixation member 20.

Smaller guide openings 83 on the targeting guide 80 are used to place atemporary k-wire fastener 41, such as by using the smaller openingfalling outside of the fixation member 20. This allows for a temporaryfixation into both the first and second bone fragments 16, 17. The drillguides 53 are placed into the appropriately sized openings 83. Thedual-diameter drill bit 90 is advanced into the drill guides 53, thescrew guides 51 connected to the hook-shaped body 55 (if necessary) andthe guide member 58 to form pilot holes in the long bone 11, as shown inFIGS. 55 and 56.

The depth of these holes are then tested using a depth gauge 102, asshown in FIGS. 50 and 51. The depth gauge 102 may also employfluorescent paint to ensure clear readability, such as on measurementnumbers and hash marks 103. The depth measurements facilitate selectionof fasteners 21, 41 of the appropriate length. If necessary, the drilledholes are then tapped (not shown) to prepare them for insertion ofthreaded fasteners 21. After tapping, the drill guides 53 are replacedwith the screw guides 51 (if necessary) and the threaded fasteners 21are advanced through the aligned openings 34, 35, 36 in the fixationmember 20 and the long bone 11 so as to connect the bone fragments 16,17, as shown in FIGS. 57, 58 and 59. The guide assembly 50 and handle 98can then be removed by removal of the temporary k-wire fastener 41 andthe screw-in drill guide 52.

In another embodiment of the present invention, the fixation member 20of the intramedullary fixation assembly 10 may include a tail portion105 extending from, or as part of, the second end 23, as shown in FIGS.13 and 14. The tail portion has a much smaller diameter or thicknessthan the curved body 24 and is relatively straight to conform to thestraightness of the shaft 14 of the long bone 11. The tail portion insome circumstances can improve the tightness of fit of the fixationmember 20 in the second bone fragment 17 with its extra length. Anotheroption for improving the fit within the second bone fragment is toemploy the use of a split tail 106, as shown in FIG. 60. The split taildefines a slot 107 that separates the split tail into two spaced armsthat are drawn against the cortical wall and urged apart as a taperedscrew 108 is advanced through the slot, as shown in FIG. 61.Alternatively, the slot 107 of the split tail 106 may also be placed inan opposite plane with a threaded opening in one of the arms so thatpassage of a standard screw therethrough pushes the arms apart foradditional stability, as shown in FIGS. 60 and 61. In anotherembodiment, the split tail portion 105 has a spring bias due toconstruction from a flexible material, such as a metal material, andwherein the split tail is defined by a coronal slot.

In still another embodiment of the present invention, the fixationmember 20 may be shaped to accommodate a driving handle 110 by havingdefined in its first end 22 a pair of U-shaped slots 112 on either sideof the fixation member, as shown in FIGS. 62 and 63. The driving handle110 includes a horseshoe or U-shaped impact end 111 that straddles thefixation member 20, inserting into the U-shaped slots 112 wherein therounded shapes avoid eccentric loading while the fixation member isbeing driven into the medullary canal 15. Clearance may also be definedin the guide assembly 50 for the impact end 111 to allow the guideassembly to remain attached during driving. As another alternative, theslots 112 may also be defined in the guide assembly 50 for driving thefixation member 20 via its attachment to the guide assembly.

In yet another embodiment of the present invention, in lieu of theafore-described connection between the prongs 59 and the concaveindentations 40, the guide member 58 may include a pair of S-curvedfittings 113, as shown in FIGS. 64, 65, 66 and 67, that are configuredto mate in a positive fit with S-curved slots 114 defined on the firstend 22 of the fixation member 20, as shown in FIGS. 68, 69 and 70.

The present invention has many advantages. For example, the inventionhas many attributes that facilitate its use for different types of humanlong bone 11 wherein the fixation device extends from the metaphysis tothe diaphysis (via the positioning of the side aperture 19), but notthrough the epiphysis, so as to avoid damaging the articular cartilage.Maintaining a constant radius of curvature near the first end 22 of thecurved body 24 allows for different sized long bones to be accommodatedmerely by extending the arc further to produce a greater “hook.” Thisovercomes the increase in not only the length of the long bone 11, butalso the increase in distance between widened end 13 and width of themedullary canal, facilitating its use on different and larger types oflong bones. It has also been determined that use of a radius ofcurvature in the range of 1.5 to 5 inches facilitates use with differenttypes of long bone 11, especially when the curved body 24 curvescontinuously along its length and the ends 22, 23 are tapered for easyinsertion.

The use of a cruciform shape and positive fit or wedge effect used forthe concave indentations 40 and the prongs 59 provides rotational andtranslational stability of the fixation member 20 when attached to theguide assembly 50. In addition, the positive fit or wedge effectoperates to center and reduce micro-motion between the targeting guide80 and the rest of the guide assembly 50. Use of the positive fit of thechannel arms 73, the locking tip 79, the slots 84 and the centeringdivot 86 is capable of achieving an accuracy in the range of onehundredths of an inch. Further, the improved positioning from thepositive fit allows the single guide assembly 50 to facilitate placementof all of the fasteners, eliminating the need to use multiple assembliesand select openings via X-rays or other visual or manual method.

Use of k-wire fasteners 41 and k-wire sized guide openings 83 andopenings 36 in the curved body 24 of the fixation member 20 allow thefixation member 20 and guide assembly 50 to be temporarily fixed to thelong bone 11 after reduction of the fracture. This allows the healthcare personnel to use both hands to insert the remaining fasteners 21,41. The cannulated, screw-in drill guide 52 with its internal guideshaft allows for insertion of fasteners 21, 41 into both the first andsecond bone fragments 16, 17 without removal or reconfiguration of theguide assembly 50. The progressively smaller diameters of the fastenerhead 42, threaded shaft 43, non-threaded shaft 43 and threaded,bone-securing end 44, and the smoothness of the non-threaded shaft,limit fretting of the threads on the bone-securing end. The stop 75prevents mounting of a left oriented targeting guide 80 to a left-handedoutrigger frame 54 and vice-versa for a right handed outrigger frame.The dual diameters 70, 71 of the drill guides 53 ensure concentricity ofthe dual-diameter drill bit 90.

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. For example, thefixation member 20 may have defined on its outer surface grooves ortexture (similar to the awl point 99) that facilitates a tight fit inthe medullary canal 15 or can hold biologic or pharmacologic materialsto facilitate bone ingrowth. Therefore, it is to be understood that theinventions are not to be limited to the specific embodiments disclosedand that modifications and other embodiments are intended to be includedwithin the scope of the appended claims. Although specific terms areemployed herein, they are used in a generic and descriptive sense onlyand not for purposes of limitation.

1. An intramedullary fixation assembly for repairing any of a pluralityof human long bone types, each of the long bones defining a medullarycanal fractured into at least a first and second adjacent bonefragments, the first bone fragment having a free end with an articularsurface thereon and defining a side aperture, said side aperturepositioned subjacent the articular surface and extending into themedullary canal, said intramedullary fixation assembly comprising: atleast a first and second fasteners, each of said fasteners having anelongate body with a head end and an opposite, bone-securing end; and afixation member having a first end, a second end and a body extendingbetween the first and second ends, said body defining a first fasteneropening positioned proximate the first end and configured to allowpassage of the first fastener therethrough and into the first bonefragment, said body defining a second fastener opening positionedproximate the second end and configured to allow passage of the secondfastener therethrough and into the second bone fragment, and said bodyhaving a radius of curvature at least near the first end within a rangeof 1.5 to 5 inches to allow passage of the fixation member through theside aperture of the first bone fragment and into the medullary canaluntil the first end of the fixation member is positioned adjacent theside aperture and within a portion of the medullary canal defined withinthe first bone fragment, and the second end of the fixation member ispositioned within a portion of the medullary canal defined within thesecond bone fragment, wherein the bone fragments are from any of theplurality of human long bone types.
 2. An intramedullary fixationassembly of claim 1, wherein the body continuously curves from its firstend to its second end.
 3. An intramedullary fixation assembly of claim1, wherein the radius of curvature is defined by a centerline extendingfrom the first end to the second end.
 4. An intramedullary fixationassembly of claim 3, wherein the body includes a smoothly curvingconcave and convex sides configured to facilitate passage of thefixation member through the side aperture and into the medullary canal.5. An intramedullary fixation assembly of claim 4, wherein at least oneof the first and second ends is tapered.
 6. An intramedullary fixationassembly of claim 2, wherein the radius of curvature is with a range ofabout 2.6 to 3.4 inches.
 7. An intramedullary fixation assembly of claim1, wherein the fixation member includes a tilt.
 8. An intramedullaryfixation assembly of claim 1, wherein at least one of the fasteners is abi-cortical fastener having a threaded shaft with a wider diameter thanthe bone-securing end and separated from the bone-securing end by anon-threaded shaft portion.
 9. An intramedullary fixation assembly ofclaim 1, wherein the second end includes a tail portion having arelatively smaller diameter than the body.
 10. An intramedullaryfixation assembly of claim 9, wherein the tail portion includes a pairof spaced arms defining a split configured to receive a fastener, andwherein insertion of the fastener forces the spaced arms apart.
 11. Anintramedullary fixation assembly of claim 1, wherein at least one of thefirst and second ends has a taper and wherein the body has a continuouscurvature extending between the ends.
 12. An intramedullary fixationassembly of claim 1, wherein the first end of the body includesadditional fastener openings extending at divergent angles with respectto the first fastener openings.
 13. An intramedullary fixation assemblyof claim 12, wherein the fastener openings at the first end of the bodyextend at an inclination angle matched to the articular surface.
 14. Anintramedullary fixation assembly of claim 13, wherein the first end ofthe fixation member defines a surface configured to extend under andsupport the articular cartilage.
 15. An intramedullary fixation assemblyof claim 14, wherein the body defines an exposed end surface accessiblethrough the side aperture and having the first fastener openingextending therethrough.
 16. An intramedullary fixation assembly of claim15, wherein the surface extending under the articular cartilage is atabout a right angle to the exposed end surface.
 17. An intramedullaryfixation assembly of claim 16, wherein the fixation member is configuredto extend from a metaphysis of the long bone to the diaphysis of thelongbone without extending into the epiphysis of the longbone, therebyavoiding damage to the articular cartilage.
 18. A bi-cortical bonefastener for use with a fixation member defining a fixation memberopening having a diameter, said bone fastener comprising: a firstbone-securing shaft portion having threads configured for fixation intoa first layer of bone, said first bone-securing shaft portion having amaximum diameter smaller than the fixation member opening diameter; amid-shaft portion adjacent the bone-securing shaft portion andconfigured to extend into the fixation member opening, said mid-shaftportion having a maximum diameter greater than the maximum diameter ofthe bone-securing shaft portion; and a second bone-securing shaftportion adjacent the mid-shaft portion and opposite the firstbone-securing shaft portion, said second bone-securing shaft portionhaving threads configured for fixation into a second layer of bone, saidsecond bone-securing shaft portion having a maximum diameter greaterthan the diameter of the mid-shaft portion.